/**
 *    Copyright 2009-2015 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.apache.ibatis.reflection.invoker;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * @author Clinton Begin
 */
/**
 * @author amiu
 * @version createtime：2018-4-30 下午2:12:26 
 * MethodInvoker方法是用反射来调用get、set方法，构造函数中
 * 获取"type"也会分get、set两种情况。
 */
public class MethodInvoker implements Invoker {

  private Class<?> type;
  private Method method;

  public MethodInvoker(Method method) {
    this.method = method;
    //若只有一个参数，则获取参数类型(set方法)
    if (method.getParameterTypes().length == 1) {
      type = method.getParameterTypes()[0];
    } else {
    //否则获取方法返回值类型(get方法)
      type = method.getReturnType();
    }
    /**
     * set方法是没有返回值的，但是有参数，参数的类型就是我们想获取的类型
     * get方法是没有参数的，我们想获取的类型就是返回值的类型
     */
  }

  @Override
  public Object invoke(Object target, Object[] args) throws IllegalAccessException, InvocationTargetException {
	//调用方法，  target是该方法的对象，args是参数
    return method.invoke(target, args);
  }

  @Override
  public Class<?> getType() {
    return type;
  }
}
